[R-390] R-390 600 ohm audio solution

[Drew P.]

Charles wrote:

> Note that all of this holds as long as the transformer is
> used with the radio's existing output transformer, to step 
> from the radio's 600 ohm output to a 4 or 8 ohm speaker 
> (with no DC current in the filament transformer primary).
> A filament transformer will not work well as a plate-to-
> voice-coil transformer (with DC current in the primary 
> winding).

A fiament transformer, if one having the right turns ratio can
be found, might be made suitable for plate-to-voice coil service
by restacking the core laminations so as to allow for an air gap.

Drew